The invention relates to a safety fitting for flame-arresting blocking of a line that conducts gas or dust containing gas.
The state-of-the-art includes safety fittings as exemplified by WO2006/12 0091 A1. The safety fitting described in WO2006/12 0091 A1 includes a sealing body which is movable inside a housing, which sealing body is guided on a guiding rod and is displaceable from a predefined open position into a sealing closed position in response to a pressure or suction wave. For holding in the open position, various spring arrangements are provided. In the closed position, the sealing body comes into contact with a radial surface on a sealing which is fixed in position. In dusty environments, this has the disadvantage that a dust plume which has formed in the region of the sealing cannot be disrupted, at least not reliably. As a result, the sealing body rests against the provided sealing at a slant and thus does not close securely. In the explosion protected area, flames may penetrate the formed gap, thus rendering the safety fitting ineffective. A further disadvantage is that the relatively thick sealings have to be machined elaborately in order to adjust them to the contour of the sealing body. In this regard, it would be desirable to be able to use standard sealings.